diff --git a/README.md b/README.md
index e70287e..38f8c6f 100644
--- a/README.md
+++ b/README.md
@@ -9,6 +9,7 @@ a calendar server
   - [ ] Proper filtering for REPORT method
   - [ ] ICS parsing
     - [x] Datetime parsing
+  - [ ] Implement PROPPATCH
 - [ ] Access Control
   - [ ] OIDC support
 - [ ] CardDAV